Automated media storage libraries are known for providing cost effective access to large quantities of stored media. The typical portable information storage media is a tape cartridge, an optical cartridge, a disk cartridge, and the like. In certain libraries, one or more portable information storage cartridges are stored in one or more cartridge magazines disposed adjacent one or more data storage devices.
Other media storage libraries include a large number of storage slots on which are stored portable information storage media. One (or more) accessors retrieve the information storage media from the storage slots and deliver the accessed media to a information storage device for reading and/or writing data on the accessed media. Suitable electronics both operate the accessor and operate the information storage devices to transmit and/or receive data from an attached on-line host computer system.
Tape cartridges containing, for example, magnetic tape, are often used in automated data storage libraries. Tape media, such a magnetic tape, is a common medium for the storage of data to be utilized by a computer. Magnetic tape has found widespread use as a data storage medium because it provides a relatively inexpensive solution for storing large amounts of data. Magnetic tape is typically stored on cartridges of which there are a variety of different types and sizes. One reason for the variety of cartridge types is the variety of different tape drives in which the cartridges are used.
Tape cartridges are comprised essentially of a cartridge shell which houses a rotatably mounted reel. Magnetic tape is wound around the hub of the reel. Reel flanges are used to contain the magnetic tape as the magnetic tape is wound on the hub. A fully loaded tape cartridge has magnetic tape wound around the hub such that the multiple layers of tape form a stack of magnetic tape extending out to near the end of the reel flanges. The tape cartridge is inserted into a tape drive mechanism which automatically threads the magnetic tape from the tape cartridge through the tape guide mechanism of the tape drive assembly. The tape is then available to the tape drive mechanism for the reading and writing of data.